Collapsible form or center.



P. OD. OCONNGR. COLLAPSIBLE FORM 0R CENTER.

APPLIUATION FILED DEG. 5, 1908.

942,922, Patented Dec. 14, 1909.

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PHILIP ODONNELL OCONNOR, OF HARTFORD, CONNECTICUT.

COLLAPSIBLE FORM OR CENTER.

Specification of Letters Patent.

Patented Dec. 14, 1909.

Application filed December 5, 1908. Serial No. 466,059.

To all whom it may concern:

Be it known that I, IDI-Inni? ODoNNnLL OCoNNon, a citizen of the United States, and a resident of Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Collapsible Forms or Centers, of which the following is a specification.

In the construction of sewers and like works from cement, brick or other materials it is advisable, and in many cases necessary, to have a forni or center to give the proper shape or contour to the interior of the work. Various devices have been provided for this purpose, some intended for one particular use and others for another particular use.

The object of my invention is to provide a form or center of the simplest construction capable of being easily and quickly operated and which is adapted for use for substantially any and every purpose for which such devices are desired.

In the drawings-Figure l is a cross sectional view showing the center in position for use. Fig. 2 is a cross sectional view showing the center after the arch has been formed, the removable section being dropped down ready to be withdrawn. Fig. 3 is a view similar to Fig. 2, the removable section having been withdrawn and the center being collapsed. Fig. a is a. central vertical section showing two centers connected end to end, one of them being extended and the other being partially collapsed. F ig. 5 is a detail view of a modification showing the center made in the form of a semi-circle.

The form or center which I have invented comprises two sections a b which are hinged together along one edge, as by the hinges o, the hinging joint being as near as possible to the exterior of the form in order that the slightest movement of the two sections toward each other will decrease the outside measurement of the form and so cause it to immediately break away from the material which has been built up around it at every oint.

Collapsible braces Z are provided to hold the form or center in its expanded position. These braces comprise a pair of rigid arms (Z d which are pivoted together, their opposite ends being pivotally secured near the free edges of the sections, as at Z2 (Z2. I prefer to provide a brace at least at each end of the form. It will be seen that by this construction the free edges of the sections are separated from one another but at the same time the form is rigid and thoroughly adapted to special uses. For instance, 1t is often desirable to use a semi-circular form such as illustrated in Fig. 5, the lower part of the work being rst completed, the form being then collapsed, removed and reversed to build the upper part of the work. Then a complete form is desired I provide a removable section c to fill in the space between the free edges of the hinged sections. Preferably I support this removable section on struts which rest on shoulders g formed on the free edges of the hinged sections. Then it is desired to remove the form the struts are knocked out, the removable seetion dropping down free from the work so that it may be readily removed; the braces will then collapse and the hinged sections swing together, when the form can be readily removed.

In some cases, as in sewer work where a number of forms are set up end to end and a considerable section of the sewer built up around them at the same time, I provide means for connecting two or more of these forms end to end, as by a U-shaped clamp It, so that a number of forms can be drawn out together after the work has set. These clamps fit down over ribs a in the interior of each form at its ends.

The sections are preferably made of stiff rigid material to prevent any buckling or springing. The shape of the cross sections of these forms or centers is not material; in some cases they may be cylindrical, in others egg-shaped, or they may be made in any shape desired.

It will be seen that the herein described device is extremely simple in its construction, is adapted to a large variety of uses, and is very quickly and easily operated.

I claim as my invention In a form or center two sections hinged together, a rigid collapsible brace connecting the space between said free edges and supthe free edges of said sections and holding ported by said struts.

them a fixed distancey apart oppositely disposed shoulders formed on the free edges of PHILIP O DONNELL OCONNOR 5 said hinged sections, struts extending be- Witnesses:

tween said free edges and resting on said D. I. KREIMENDAHL,

shoulders, anda removable section filling LENA E. BERKVOIToI-i. 

